Abstract 18647: Functional Evaluation of a Patient-specific 3D Printed Model of Aortic Regurgitation

Abstract

Introduction: Quantification of aortic regurgitation (AR) can be challenging using non-invasive imaging methods. In vitro simulation of patient-specific AR would allow reference standard measurement of the regurgitant flow volume and a comparison against Doppler methods of AR quantification. Hypothesis: We sought to build a functional patient-specific 3D printed model of the aortic valve (AV) and to replicate AR Doppler parameters recorded during a clinical echocardiogram. Methods: We identified a clinical multi-detector CT dataset (mid-diastolic phase) of a selected patient with generative AV disease and mild AR. Segmentation software was used to segment the calcified and non-calcified components of the aortic root. Fused-material 3D printed was used to create a patient-specific physical model of the aortic root, AV cusps, regional calcification and left ventricle. The 3D model was coupled to a flow loop to replicate the trans-valvular hemodynamic conditions recorded during a clinical echocardiogram. The accuracy of hemodynamic replication was evaluated using Doppler imaging and compared to the clinical study. Results: Functional Doppler imaging of the 3D printed model demonstrated similar quantitative parameters to the clinical Doppler findings, respectively; peak velocity 4.6 vs 4.7 m/s; regurgitant time 460 vs 458 ms; pressure half time 312 vs 331 ms; time-velocity index 167vs 162 cm. Regurgitant jets were qualitatively similar. Doppler velocity profiles for the patient and the 3D model, shown in Figure 1. We demonstrate an in vitro method to mimic and quantify AR using patient-specific anatomic and functional 3D modeling. Conclusion: We describe the development of a functional patient-specific 3D printed model of the AV replicating both the geometry and function of AV regurgitation. This initial functional modeling may extend to studies of AR severity using novel imaging modalities (e.g. 3D color Doppler) or structural heart interventions.